1. Technical Field
Various embodiments generally relate to a semiconductor integrated circuit, and more particularly, to a regulator circuit and a semiconductor apparatus having the same.
2. Related Art
A semiconductor integrated circuit is a complex electronic device including a great number of electronic elements mounted on a substrate. The semiconductor integrated circuit also has a subminiature structure. The semiconductor integrated circuit requires power for operation. A voltage supply unit is a circuit for converting an external voltage into an internal voltage. The voltage supply unit supplies a preset level of voltage to the respective elements on the substrate.
In general, a low-level voltage is supplied to the semiconductor integrated circuit. In many cases, however, the semiconductor integrated circuit may require a high voltage for internal operation. Thus, the voltage supply unit may include a pump capable of generating a high voltage. The high voltage may be generated by pumping an external voltage inputted to the voltage supply unit at a low level. Furthermore, one of factors for determining the operating speed of the semiconductor integrated circuit is how fast the pump can raise a voltage to a target level.
For example, a flash memory apparatus requires a high voltage during a program or erase operation. The voltage supply unit must be able to generate a preset level of program voltage or erase voltage according to the operation mode of the flash memory apparatus. Furthermore, as the time required for generating and providing the preset level of program voltage or erase voltage decreases, the flash memory apparatus can reduce the entire time required for performing a program or erase operation.
The output voltage of the voltage supply unit must be constantly maintained at the target level. To constantly maintain the target level of the output voltage of the voltage supply unit a regulator circuit may be used.
The regulator circuit detects a pumped voltage, and determines whether to operate the pump according to a comparison result between the detected voltage and a reference voltage.
The semiconductor integrated circuit requires a different voltage level depending on the operation mode. Thus, according to the operation mode, the pump generates a preset level of high voltage. The generated high voltage must be able to maintain the corresponding level in the regulator circuit. Furthermore, when the required voltage level is changed, the output voltage of the pump may be changed. In this case, the regulator circuit is required to maintain the high voltage at the changed level.
Such a high-voltage supply operation may serve as a factor in determining the operation reliability as well as the operating speed of the semiconductor integrated circuit.